Near nonexistent. Battery size requirements and battery charging rates make EV RVS either really expensive and really impractical for distance travel. You would need to put a huge battery (say, 300 KwH, which would cost $60,000 just for the battery), to get a reasonable range of 200-300 miles between charges, depending upon the efficiency of your RV. And then, even at a level 3 DCFC Charging station (providing 50 KW) you're looking at 6 hrs of charging to fully charge the battery.

You know how much new RVs cost right? 200-400k is not unusual for a 'big' RV.

Also, with a bigger battery comes higher limits on how fast you can charge. If you have a 300kWh battery you should be able to charge it at 300kW all day long.

That said, it doesn't really exist since there is no market for it at the moment. RV sales aren't exactly high, so the niche for EV RVs is even smaller. Plus there's no real infrastructure out for it now.

I suspect once EV Semis become more mainstream we'll see that trickle down to RV users. They can charge at the same place a semi would charge at.

The thing about RVs is that generally, you won't have to drive them often. Average solar panel produces about 15 watts per square foot, so over a course of a month with about 7 hours of sun a day, that is 3 kwh/square foot. So 50 square feet of panels, which is the total area of a large bed, will get you half the range over a month.

Also, there will undoubtably be hybrid options where you can have a multi fuel generator charging your batteries.

In this post-apocalyptic scenario I think the range would be secondary to using the battery for day-to-day living. The RV could have solar and keep the battery topped off all the time.

The Ford F150 Lightning has a number of features made for pulling a trailer.

https://www.ford.com/trucks/f150/f150-lightning/2022/#towing...

That and a truck camper[0] is probably the way I would go.

[0]https://www.lancecamper.com/truck-campers/